Rotary sanders, grinders, polishers, buffers, and cleaners are used in a wide range of applications, including carpentry, metal working, vehicle detailing, and vehicle repair. These tools can also be used with diverse substrates, including marble, glass, upholstery, wood, metal and painted surfaces. The tools are sometimes adapted for specialized applications, for example when there is risk of damaging the substrate. One such application is in automotive and marine exterior detailing. Car exteriors typically include several layers of paint, which are then topped with a protective clear coat layer. Boats typically utilize a gel coat in lieu of the protective clear coat layer that may be treated in a similar fashion to automotive finishes. To obtain an aesthetically pleasing shine, car enthusiasts apply a wax or liquid polish composition to the exterior of the car and then use a rotary polisher to spread the composition and remove swirls and minor scratches from the clear coat layer.
Simple rotary (or “single-action”) polishers use a work member that rapidly spins about a fixed axis of rotation relative to the polishing device. While these devices are capable of polishing the substrate at a high cut rates, this action can also generate significant heat because the polishing head rotates at such high speeds. In the hands of an untrained operator, a single-action polisher can generate enough heat to risk “burning” the paint, which refers to the undesirable removal of paint residing below the clear coat surface. Decreasing the rotational speed of the work member can reduce this risk, but doing so can also reduce polishing efficiency below acceptable levels.
The risks associated with a single-action polisher can be substantially mitigated while maintaining polishing efficiency by using an oscillating, dual-action polisher. Dual action polishers use a work member that spins about a central spindle, while the spindle itself rotates around an eccentric offset. Like a planet orbiting around the sun, the head of a dual-action polisher spins about a first axis while orbiting around a second axis displaced from the first axis. For this reason, these dual-action devices are also sometimes referred to as orbital polishers. The combined rotating/orbiting motion dissipates heat and can effectively prevent the polisher from burning the paint. This safety feature makes dual-action devices an attractive option for hobbyists and professionals alike.